The objective of this article is to analyze Emilio Mira's contributions to applied psychology in the workplace. Emilio Mira's professional life can be summarized in three key stages: his training and professional activity in Spain until 1939; his international travels and stays between 1939 and 1945; and his time in Latin America from 1945 until his death in 1964. He contributed to the development of applied psychology in Europe and Latin America. He directed the Barcelona Institute of Psychotechnics, where two important international conferences on the Scientific Organization of Work were held in 1922 and 1930. A physician trained along the same lines as Ramón y Cajal and Simarro, Emilio Mira is an intriguing and versatile figure who made notable contributions in fields such as psychopathology, school hygiene, diagnosis, education, and vocational guidance. He promoted the development of technical school and vocational guidance in Spain and in many American countries, where professional selection activities occupied a prominent place in the Psychotechnical Institutes he directed. In this line, in his work "Manual de Orientación Profesional" he proposes some relevant aspects such as psychophysiotechnical classifications of tasks and professions, job cards, programs for diagnosing aptitudes and personality for professional guidance and instruments to carry them out, models for collecting and recording school, physiopathosomatic or social background, questions for directed autobiographies, intimate questioning... Emilio Mira carried out a relevant activity in Latin America from 1940 until his death in 1964. He exerted a notable influence on the development of applied psychology in Latin America, particularly in Brazil, Cuba, Argentina, Chile, Uruguay. In all the countries where he ran psychotechnical and career guidance centers, Emilio Mira placed great emphasis on career guidance and selection processes.